This invention relates to an improved fluidized patient support system that is of particular advantage to burn patients, as well as other patients who are immobilized for extended recuperative periods.
Historically, hospital beds for patients have in general been conventional where, though adjustable as to height and attitude, a mattress-springs arrangement has been provided for receiving the patient thereon covered, of course, with appropriate bed clothing. Particular problems have developed in use of the conventional hospital beds where the patients, due to prolonged contact with the support surface in generally immobile conditions, have developed decubitus ulcers or bed sores, as a result of pressure points between the support surface and certain portions of the patient's body. Additionally, in the case of burn patients where the severity of the injury or wound was such that the patient was affected over a significant portion of his body, the conventional bed presented problems not only with the healing process due to contact between raw areas of the human body and the support, but also due to fluids exuding from the patient's body. In like fashion, other types of injuries and reasons for confinement have presented problems with the conventional hospital bed.
In order to obviate some of the problems inherent with the conventional hospital bed, fluidized patient support structures have been developed as exemplified in the Hargest U.S. Pat. No. 3,428,973 in which a tank is provided, partially filled with a mass of granular material which is received atop a diffuser surface and is covered with a loose fitting flexible patient contact sheet or surface. Fluid, such as air, is provided in a plenum chamber beneath the diffuser surface and is forced through the diffuser surface for fluidization of the granular material, preferably ceramic spheres, with adequate force that a patient received on the flexible sheet is suspended on the fluidized bed. In this fashion, very gentle forces are imparted to the affected body portions of the patient, whereby the incidence of development of decubitus ulcers is reduced and whereby an individual experiencing trauma, such as produced by severe burns may rest comfortably.
In similar fashion, a further fluidized patient support structure is disclosed in the Hargest U.S. Pat. No. 3,866,606 which structure has the same basic elements of that mentioned above with the addition of control means to cyclically fluidize the granular material, also preferably ceramic spheres. In a non-fluidized state, the patient settles into the mass of granular materials which becomes a rigid, body contoured, structure against which the patient's body may be placed in traction. In like fashion, the cyclic effect of fluidizing-rigidifying the mass of granular material permits variation in patient attitude, again towards variance of constant pressures on affected body portions and thus reduction of the incidence of development of decubitus ulcers.
In both of the fluidized patient support systems described above, there is, for an adult patient, generally a minimum depth of about 12 inches of fluidized granular material located above the diffuser board to preclude any contact between the body of the patient and the diffuser board when the patient is in a sitting position on the bed.
In other support systems, fluid support means may be provided as exemplified by air filled structures. These other fluid filled support structures through an improvement over the conventional mattress supports, are not considered to be as effective as the fluidized support systems noted above, are generally much less expensive, and thus more available for general use. In all of the structures mentioned above, it is important from a standpoint of comfort and effectiveness of support, that the patient have adequate support beneath the body to hold the body above an underside of the support structure. In other words, it is highly desirable that the patient not "bottom out" against an underlying rigid surface of the support system.
Obviously, in any fluid supported system, a number of problems may evolve resulting in inadequate fluid support of a patient. Such problems can result from inadequate fluid supply, leakage of fluid from the structure and the like. The support system of the present invention provides an arrangement for sensing such inadequate patient support and, depending on the fault, corrects same or alerts attending personnel to the problem which is not simply correctable by introduction of further fluid, reinflation or the like. There is no known prior art that anticipates or suggests the invention of the present invention.